Motorcycle Anatomy Expert Article

The automotive experts at Robson Forensic have developed a simple motorcycle anatomy overview for clients who may not be familiar with the design elements of a motorbike.

Motorcycle Fatalities

The CDC reports that 4502 motorcyclists died in motorcycle crashes in 2010 and that motorcycle fatalities have increased 55% since 2000. The experts at Robson Forensic have investigated hundreds of motorcycle crashes. The crashes typically involve crash reconstruction, evaluation of operator actions, alleged defects related to design, manufacture or maintenance and issues related to roadways. The experts at Robson Forensic can assist you with these investigations.

Simplified Motorcycle Anatomy

Technical Concepts

Frame - The foundation for the motorcycle. The design varies greatly and typically includes metal components joined by welding. Materials range from steel tubing to extruded aluminum.

Front Suspension - Telescopic front forks are the most popular front suspension on a motorcycle. They consist of a tube sliding inside a slider. Internal parts include springs, oil and damping components.

Rear Suspension – A swingarm with a single or dual shock absorber is typical. Linkage arrangements enable varying levels of suspension travel range.

Rake Angle - The angle that the steering head axis makes relative to a vertical line drawn to the ground. “Choppers” have a larger rake angle than sportbikes. Rake angle affects the “trail” measurement and motorcycle handling.

Trail - The distance the front tire contact patch is behind a line drawn from the steering axis to the ground. Trail affects the motorcycle handling.

Wheelbase - The distance between the front axle and rear axle. Wheelbase affects the handling of the motorcycle.

Handlebar Height – Some states have regulations for how high the handlebars can rise above the seat or the rider’s shoulders.

Seat Height – The seat height on a motorcycle can range from 26” for cruisers up to 34” for dual purpose motorcycles. The seat height is important to consider for smaller motorcyclists.

Featured Experts

Peter J. Leiss, Automotive Engineer & Crash Expert

Peter J. Leiss, P.E., C.F.E.I., C.V.F.I.

Automotive Engineer & Crash Expert
PJ is an expert in vehicle engineering and crash reconstruction. He commonly investigates and testifies in matters pertaining to vehicle crashworthiness, vehicle performance/handling dynamics, and… read more.
Roland Hoover, Automotive Engineer, Motorcycle & Bicycle Expert

Roland Hoover

Automotive Engineer, Motorcycle & Bicycle Expert
Roland Hoover is a mechanical engineer with broad experience in automotive and motorcycle engineering. His career includes more than 20 years of engineering experience at OEM vehicle manufacturers,… read more.

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